Display name on email alias is not used

Steps to reproduce

Sending email from an added alias address will use the main display name set for the mail account when sending.

Example: I have one mail account with 2 email aliases on it:

main@example.com (main address that was used to log in, configured with the name "Main")
extra@example.com (This is added as an alias in the options of the mail account in the app, display name set to "Extra")

Sending mail from "main" works as expected, however sending as "extra" will use the display name "Main".

This has been tested on two separate Nextcloud instances (one self-hosted and one managed provider).

I have verified that the mail server itself does not do anything weird. I've done this adding the same account to the email client in Vivaldi Browser, and here it allows sending mail from the same mailbox account but using separate alias addresses with different display names. And the receiver will see the display name set for the alias.

Expected behavior

Sending from aliases will use the defined display name set on the alias. And the receiver will see the display name set for the alias.

Actual behavior

Sending from aliases uses the primary display name. The receiver is always getting the primary display name set for the mailbox in the mail app.

Mail app version

3.7.8

Mailserver or service

Stalwart mail-server (self-hosted)

Operating system

Ubuntu 22.04.4 LTS (for the self hosted instance)

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database

MySQL

Additional info

No response

nextcloud / mail